Aside from Clover-lookalike, that dark-skinned woman on the right looks like Allice. And this Fi has some resemblance to Santa.

So, seems like this'll have doors and bracelets as well. They might need to change some things in the door and digital root system, as some people already know its secrets from 999. Or the surprises will be limited to the story only. I guess it will happen in the future of 999, if it has more than a spiritual connection. Could some of those characters be children/grandchildren of 999 characters?

Spoiler for Nine Persons, Nine Hours, Nine Doors:

Could Junpei's epiphanies in the true end have some connection to this story? Maybe we'll even see continuation to the mysterious safe end.

Well, looking forward to hearing more about it, 999 was a great game.
Looks like I have to get Vita after all, or the 3DS...